Conductive material and process for preparing the same

Abstract

The invention provides a conductor comprising a reaction-sintered body of a conductive nitride produced from a powder of at least one metal selected from Ti, Zr, V, Nb, Ta, Cr, Ce, Co, Mn, Hf, W, Mo, Fe, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Yb, Lu, Th and Ni, and a process for producing such conductor by heating a molding containing a metal powder in a nitriding gaseous atmosphere containing no CO gas.

What is claimed is: 
     
       1. A conductor material made of an electrically conductive nitride produced by reaction sintering a shaped body consisting essentially of (a) particles of at least one metal from Ti, Zr, V, Nb, Ta, Cr, W, Fe and Ni, said particles being free of Si, and (b) particles of at least one inorganic compound selected from a carbide, nitride, oxynitride, oxide silicide and boride in a CO-free nitrogen-containing atmosphere at a temperature below the melting point of the mixed powder of (a) and (b), so that said particles of said at least one inorganic compound are linked to another by particles and whiskers of nitride of said at least one metal formed by said reaction sintering, said conductor material having an electrical resistivity of 10 14  to 10 -5  Ω cm, wherein said conductor material has a porosity below 30%. 
     
     
       2. The conductor material made of an electrically conductive nitride according to claim 1 having an electrical resistivity at room temperature of 1×10 -5  Ω cm to 5×10 -5  Ω cm. PG,41 
     
     
       3. A conductor material made of particles and whiskers of an electrically conductive nitride produced by reaction sintering a shaped body consisting essentially of (a) particles of at least one metal from Ti, Zr, V, Nb, Ta, Cr, W, Fe and Ni, said particles being free of Si, and (b) particles of at least one inorganic compound selected from carbide, nitride, oxynitride, oxide, silicide and boride in a CO-free nitrogen-containing atmosphere at a temperature below the melting point of the mixed powder of (a) and (b), said conductor material having an electrical resistivity of 10 14  to 10 -5  Ω cm, wherein said conductor material has a porosity below 30%. 
     
     
       4. A conductor material made of an electrically conductive nitride produced by reaction sintering a shaped body consisting essentially of (a) particles of at least one metal from Ti, Zr, V, Nb, Ta, Cr, W, Fe and Ni, (b) particles of at least one of silicon and aluminum, and (c) particles of at least one inorganic compound selected from a carbide, nitride, oxynitride, oxide, silicide and boride, wherein said shaped body has a particle volume packing density of at least 60 vol % and said particles of at least one of silicon and aluminum are contained in an amount of 90% by volume or less, in a CO-free nitrogen-containing atmosphere at a temperature below the melting point of the mixed metal powder of (a), (b) and (c), so that said particles of said at least one inorganic compound are linked to one another by particles and whiskers of nitride of said at least one metal formed by said reaction sintering, said conductor material having an electrical resistivity of 10 14  to 10 -5  Ω cm or less, wherein said conductor material has a porosity below 30%. 
     
     
       5. The conductor material made of an electrically conductive nitride according to claim 4, having an electrical resistivity at room temperature of 1×10 -5  Ω cm to 5×10 -5  Ω cm. 
     
     
       6. A conductor material made of particles and whiskers of an electrically conductive nitride produced by reaction sintering a shaped body consisting essentially of (a) particles of at least one metal from Ti, Zr, V, Nb, Ta, Cr, W, Fe and Ni, (b) particles of at least one of silicon and aluminum, and (c) particles of at least one inorganic compound selected from a carbide, nitride, oxynitride, oxide, silicide and boride, wherein said shaped body has a particle volume packing density of at least 60 vol % and said particles of at least one of silicon and aluminum are contained in an amount of 90% by volume or less, in a CO-free nitrogen-containing atmosphere at a temperature below the melting point of the mixed metal powder of (a), (b) and (c), said conductor material having an electrical resistivity of 10 14  to 10 -5  Ω cm or less, wherein said conductor material has a porosity below 30%. 
     
     
       7. A ceramic composite article which comprises a laminate of at least first and second layers, each of said first and second layers being made of the reaction-sintered conductor materials claimed in any one of claims 1, 3, 4 and 6, said first layer having a different electrical resistivity than said second layer, and said first and second layers being integrally sintered. 
     
     
       8. The conductor material made of an electrically conductive nitride according to claim 3, having an electrical resistivity at room temperature of 1×10 -5  Ω cm to 5×10 -5  Ω cm. 
     
     
       9. The conductor material made of an electrically conductive nitride according to claim 6, having an electrical resistivity at room temperature of 1×10 -5  Ω cm to 5×10 -5  Ω cm. 
     
     
       10. A conductor material according to claim 4, wherein said (a) particles of at least one metal are selected from the group consisting of Ti, Zr, V, Nb, Ta, Cr, W and Ni.